Click to explore the various exposure modes on many cameras.

Modern digital cameras have sophisticated ways of controlling the aperture and shutter speed. In fully automatic mode the camera sets them both to produce the best possible exposure. However, there are other exposure modes that are widely used in digital photography. All modes give equally good results in the vast majority of photographic situations. However, when you photograph in specific kinds of situations, each of these exposure modes may have certain advantages. Let's take a look at the modes you can expect to find on some or all digital cameras.

• Automatic mode sets the shutter speed and aperture without your intervention. This mode allows you to shoot without paying attention to settings so you can concentrate on composition and focus.
• Scene modes have preselected settings for specific situations such as landscapes, portraits, night portraits, sports, and close-up photography.
• Programmed mode is just like full auto in that it sets the aperture and shutter speed for you so you can concentrate on composition and action. When in this mode, many cameras have a flexible program mode that lets you select from a series of paired aperture and shutter speed combinations that yield the same exposure as that recommended by the camera but which give you control over depth of field and motion.

One reason to use flexible program mode is that it doesn't let you choose settings that exceed your camera's exposure limits. In shutter-priority and aperture-priority mode it's possible to select a setting that can't be matched. For example, in aperture-priority mode, you may pick an aperture that's so large the camera doesn't have a shutter speed that's fast enough to prevent overexposure. Although aperture-priority and shutter-priority modes usually warn you when this happens, you won't always notice the warning. Here are some of the situations you avoid when using programmed mode.

• Shutter-priority mode lets you choose the shutter speed you need to freeze or deliberately blur camera or subject movement and the camera automatically sets the aperture to give you a good exposure. You select this mode when the portrayal of motion is most important. For example, when photographing action scenes, such as those encountered by wildlife photographers, sports photographers, and photojournalists, shutter-priority mode might be best. It lets you be sure your shutter speed is fast enough to freeze the action or slow enough to blur it.
• Aperture-priority mode lets you select the aperture needed to obtain the depth of field you want and the exposure system automatically sets the shutter speed to give you a good exposure. You select this mode whenever depth of field is most important. To be sure everything is sharp, as in a landscape, select a small aperture. The same holds true for close-up photography where depth of field is a major concern. To throw the background out of focus so it's less distracting in a portrait, select a large aperture.
• Manual mode lets you select both the shutter speed and the aperture. You normally use this mode only when the other modes can't give you the results you want. Some cameras have a bulb setting in this mode that lets you capture time exposures such as light trails at night.